Massive parallel sequencing unveils homologous recombination deficiency in follicular dendritic cell sarcoma.

Standardized treatment options are lacking for patients with unresectable or multifocal follicular dendritic cell sarcoma (FDCS) and disease-related mortality is as high as 20%. Applying whole genome sequencing (WGS) in one case and whole exome sequencing (WES) in additional twelve, this study adds information on the molecular landscape of FDCS, expanding knowledge on pathobiological mechanisms and identifying novel markers of potential theragnostic significance. Massive parallel sequencing showed high frequency of mutations on oncosuppressor genes, particularly in RB1, CARS and BRCA2 and unveiled alterations on homologous recombination DNA damage repair related genes in 70% (9/13) of cases. This indicates that patients with high stage FDCS may be eligible for poly ADP ribose polymerase inhibition protocols. Low tumor mutational burden was confirmed in this study despite common PDL1 expression in FDCS arguing on the efficacy of immune checkpoint inhibitors. CDKN2A deletion, detected by WGS and confirmed by FISH in 41% of cases (9/22) indicates that impairment of cell cycle regulation may sustain oncogenesis in FDCS. Absence of mutations in the RAS/RAF/MAPK pathway and lack of clonal hematopoiesis related mutations in FDCS sanction its differences from dendritic cell-derived neoplasms of haematopoietic derivation. WGS and WES in FDCS provides additional information on the molecular landscape of this rare tumor, proposing novel candidate genes for innovative therapeutical approaches to improve survival of patients with multifocal disease.

Prevalence and reasons for non-nursing tasks as perceived by nurses: Findings from a large cross-sectional study.

AIM: The aim of this study is to describe the prevalence and reasons for non-nursing tasks as perceived by nurses. BACKGROUND: Four types of non-nursing tasks have been identified to date: (a) auxiliary; (b) administrative, (c) expected by allied health care professionals; and (d) medical. However, no studies on a large scale have been performed with the aim of identifying the prevalence of all of these non-nursing tasks, and factors promoting or hindering their occurrence, given that they represent a clear waste of nurses' time. METHODS: A cross-sectional study in 2017, following The Strengthening the Reporting of Observational studies. All active nurses registered in an Italian provincial Nursing Board (=1331) willing to participate were involved. A questionnaire survey exploring the nature of the nursing tasks performed in daily practice and the underlying reasons was administered via paper/pencil and e-mail. RESULTS: A total of 733 nurses participated of which 94.5% performed at least one type of non-nursing task, mainly administrative and auxiliary. Auxiliary tasks are less likely among nurses working in a community (odds ratio [OR] 0.43, 95% CI 0.29-0.63, p < .01) or in a residential (OR 0.41, 95% CI 0.23-0.72, p < .01) setting, in critical (OR 0.29, 95% CI 0.16-0.54, p < .01) or surgical (OR 0.37, 95% CI 0.19-0.75, p < .01) hospital settings, and when they deal with unexpected clinical events (OR 0.58, 95% CI 0.44-0.77, p < .01). Greater adequacy of nursing resources decreases the occurrence of auxiliary tasks (OR 0.98, 95% CI 0.97-0.99, p < .01), whereas the need to compensate for a lack of resources (OR 1.44, 95% CI 1.07-1.93, p < .01) increases it. CONCLUSIONS: Around one-third of shift time is devoted to non-nursing tasks; working in a hospital, in medical units, with lack of resources and with patients with predictable clinical conditions might increase the occurrence of auxiliary tasks. IMPLICATIONS FOR NURSING MANAGEMENT: Strategies to increase the time available for nursing care should consider the type of tasks performed by nurses, their antecedents and the value added to care in terms of patient' benefits.

p.Ser891Ala RET gene mutations in medullary thyroid cancer: Phenotypical and genealogical characterization of 28 apparently unrelated kindreds and founder effect uncovering in Northern Italy.

Applying genetic screening in medullary thyroid cancer (MTC) patients we identified an unexpectedly high frequency of c.2671T>G, p.Ser891Ala RET mutation carriers. Our aim was to: (a) deeply characterize the clinical expression of this mutation, (b) identify the presence of a founder effect in our region. Genetic analysis was performed in 251 relatives from 28 Ser891Ala kindreds, among 108 p.Ser891Ala asymptomatic carriers, 64 were submitted to thyroidectomy: mean age for 10 subjects presenting C-cells hyperplasia was 30.2 ± 13.7 years, raising to 37.9 ± 10.3 in 14 subjects with micro-MTC and to 55.0 ± 14.7 years in 39 subjects with MTC. Age-related progression across histopathological groups CCH/microMTC and MTC were statistically significant: genetic screening in Ser891Ala families could be safely postponed at the age of 14. To investigate the hypothesis of a common ancestor for Ser891Ala mutation we genotyped for 18 polymorphic microsatellite markers encompassing RET locus all subjects belonging to Ser891Ala families and we identified a founder effect, estimating the age of a common ancestor, dating back to 1493 AD. Ethnographic data collected in historical archives support laboratory results; the high prevalence of this mutation in our region could suggest the hypothesis of a population study to realize a preventive intervention in a rare neoplastic disease.

Relationship between different subpopulations of circulating CD4+ T lymphocytes and microvascular or systemic oxidative stress in humans.

BACKGROUND AND OBJECTIVE: Different components of the immune system, including innate and adaptive immunity (T effector lymphocytes and T regulatory lymphocytes - TREGs) may be involved in the development of hypertension, vascular injury and inflammation. However, no data are presently available in humans about possible relationships between T-lymphocyte subtypes and microvascular oxidative stress. Our objective was to investigate possible relationships between T-lymphocyte subtypes and systemic and microvascular oxidative stress in a population of normotensive subjects and hypertensive patients. PATIENTS AND METHODS: In the present study we enrolled 24 normotensive subjects and 12 hypertensive patients undergoing an elective surgical intervention. No sign of local or systemic inflammation was present. All patients underwent a biopsy of subcutaneous fat during surgery. A peripheral blood sample was obtained before surgery for assessment of T lymphocyte subpopulations by flow cytometry and circulating indices of oxidative stress. RESULTS: A significant direct correlation was observed between Th1 lymphocytes and reactive oxygen species (ROS) production (mainly in microvessels). Additionally, significant inverse correlations were observed between ROS and total TREGs, or TREGs subtypes. Significant correlations were detected between circulating indices of oxidative stress/inflammation and indices of microvascular morphology/Th1 and Th17 lymphocytes. In addition, a significant inverse correlation was detected between TREGs in subcutaneous small vessels and C reactive protein. CONCLUSIONS: Our data suggest that TREG lymphocytes may be protective against microvascular damage, probably because of their anti-oxidant properties, while Th1-Th17 lymphocytes seem to exert an opposite effect, confirming an involvement of adaptive immune system in microvascular damage.

Yeast model for evaluating the pathogenic significance of SDHB, SDHC and SDHD mutations in PHEO-PGL syndrome.

SDH genes, encoding succinate dehydrogenase, act as tumour suppressor genes, linking mitochondrial dysfunction with tumourigenesis. Heterozygous germline mutations in SDHA, SDHB, SDHC, SDHD and in the assembly factor encoding gene SDHAF2 have all been shown to predispose to heritable endocrine neoplasias such as pheochromocytomas (PHEO) and paragangliomas (PGLs) called 'PHEO-PGL syndrome'. SDH genes mutations, in addition to deletions or truncations which are most likely pathogenic, often include missense substitutions which can be of uncertain significance. Unclassified missense substitutions may be difficult to interpret unless the cause-effect link between mutation and the disease is established by functional and in silico studies or by the familial segregation with the phenotype. Using the yeast model, here, we report functional investigations on several missense SDH mutations found in patients affected by pheochromocytomas or paragangliomas. The aim of this study was to evaluate whether and to which extent the yeast model may be useful for establishing the pathological significance of missense SDH mutations in humans. The results of our study demonstrate that the yeast is a good functional model to validate the pathogenic significance of SDHB missense mutations while, for missense mutations in SDHC and SDHD genes, the model can be informative only when the variation involves a conserved residue in a conserved domain.

When the diagnosis is written in the DNA: a case of erythropoietic protoporphyria in a patient with a chromosome-18 deletion.

In this case study, we describe a 21-year-old man with erythropoietic protoporphyria who sought medical attention in April 2022 for diffuse edema and erythema of the hands. These symptoms had been present since childhood and usually occurred soon after sun exposure. The patient's medical history showed that chromosome 18's long arm had partially deleted. We performed a number of tests, including measuring total erythrocyte protoporphyrin levels and utilizing a spectrofluorometer to assess the fluorometric emission peak of plasma porphyrins, based on the patient's medical history and clinical symptoms. Furthermore, a genetic analysis identified an intronic variant on one allele, c.315-48T>C (IVS3-48T>C), which is categorized as a susceptibility polymorphism, and a complete deletion of the ferrochelatase gene on the other allele. The patient's clinical condition improved following the June 2022 afamelanotide implant procedure.

Progesterone receptor is constitutively expressed in induced Pluripotent Stem Cells (iPSCs).

Induced Pluripotent Stem Cells (iPSCs) are nowadays a common starting point for wide-ranging applications including 3D disease modeling (i.e. organoids) and in future regenerative medicine. Physiological processes like homeostasis, cell differentiation, development and reproduction are tightly regulated by hormones through binding to their transmembrane or nuclear receptors of target cells. Considering their pleiotropic effect, take into account also their expression in an iPSCs-based disease modeling would better recapitulate the molecular events leading to 3D organoid development and disease study. Here we reported the expression pattern of estrogen receptor (ERα) and progesterone receptor (PR) in four different iPSCs, obtained from CD34 + progenitor cells and skin fibroblasts with four different methods. Expression of ERα and PR mRNA were significantly downregulated in iPSCs as well as fibroblasts compared to MCF7 positive control. Immunofluorescence (IF) staining detected only the expression of PR protein in all the different iPSCs cell lines, while ERα was not detectable. By flow cytometry analysis we observed that the ~ 65% of the total population of iPSCs cells expressed only PR, with 100% fold increase compared to HSPCs and fibroblasts, while ERα was not expressed. Our results collectively demonstrated for the first time that the reprogramming of somatic cells into iPSCs leads to the expression of PR receptor.

New pathogenic variants in ARMC5 gene in a series of Italian patients affected by primary bilateral macronodular adrenocortical hyperplasia (PBMAH).

BACKGROUND: To perform genetic screening for ARMC5 gene germline pathogenic variants in patients with primary bilateral macronodular adrenal hyperplasia (PBMAH). SUBJECTS AND METHODS: In a group of 10 PBMAH patients, we performed complete sequencing of the coding region of the ARMC5 gene and MLPA analysis for large deletion detection. In subjects with the ARMC5 variant, we searched ARMC5 gene somatic variants on tumor samples. RESULTS: Among 10 PBMAH patients, we identified four ARMC5 germline variants (40%). One variant, c:174dupC p.Glu59Argfs*44, was already known; one variant p.Gly323Asp, was already reported and classified as likely disease-causing VUS (class 3-4); two variants p.Leu596Arg and p.Arg811Pro, were never reported before. For p.Gly323Asp and p.Arg811Pro, we identified second deleterious variants at the somatic level, enforcing the possible pathogenic effect of germline variants. CONCLUSIONS: Our results underscore the importance of performing genetic testing also in sporadic PBMAH patients and broaden the spectrum of molecular variants involved in PBMAH syndrome.

Spectrum and prevalence of FP/TMEM127 gene mutations in pheochromocytomas and paragangliomas.

CONTEXT: Pheochromocytomas and paragangliomas are genetically heterogeneous neural crest-derived neoplasms. We recently identified germline mutations of the novel transmembrane-encoding gene FP/TMEM127 in familial and sporadic pheochromocytomas consistent with a tumor suppressor effect. OBJECTIVES: To examine the prevalence and spectrum of FP/TMEM127 mutations in pheochromocytomas and paragangliomas and to test the effect of mutations in vitro. DESIGN, SETTING, AND PARTICIPANTS: We sequenced the FP/TMEM127 gene in 990 individuals with pheochromocytomas and/or paragangliomas, including 898 previously unreported cases without mutations in other susceptibility genes from 8 independent worldwide referral centers between January 2009 and June 2010. A multiplex polymerase chain reaction-based method was developed to screen for large gene deletions in 545 of these samples. Confocal microscopy of 5 transfected mutant proteins was used to determine their subcellular localization. MAIN OUTCOME MEASURES: The frequency and type of FP/TMEM127 mutation or deletion was assessed and correlated with clinical variables; the subcellular localization of 5 overexpressed mutants was compared with wild-type FP/TMEM127 protein. RESULTS: We identified 19 potentially pathogenic FP/TMEM127 germline mutations in 20 independent families, but no large deletions were detected. All mutation carriers had adrenal tumors, including 7 bilateral (P = 2.7 × 10(-4)) and/or with familial disease (5 of 20 samples; P = .005). The median age at disease onset in the FP/TMEM127 mutation group was similar to that of patients without a mutation (41.5 vs 45 years, respectively; P = .54). The most common presentation was that of a single benign adrenal tumor in patients older than 40 years. Malignancy was seen in 1 mutation carrier (5%). Expression of 5 novel FP/TMEM127 mutations in cell lines revealed diffuse localization of the mutant proteins in contrast with the discrete multiorganelle distribution of wild-type TMEM127. CONCLUSIONS: Germline mutations of FP/TMEM127 were associated with pheochromocytoma but not paraganglioma and occurred in an age group frequently excluded from genetic screening algorithms. Disease-associated mutations disrupt intracellular distribution of the FP/TMEM127 protein.

Non-nursing tasks as experienced by nursing students: Findings from a phenomenological interpretative study.

BACKGROUND: During their clinical learning experience, students are exposed to the nursing profession as a powerful structural reality, experiencing the so-called professional socialisation, a process recognised as the basis of professional identity. Inside this process, students progressively acknowledge their professional identity as being composed of several competencies and, among these, also non-nursing tasks. OBJECTIVES: To explore non-nursing tasks in the context of nursing students' clinical learning experiences. DESIGN: An interpretative phenomenological study design was performed and carried out in 2016. The COnsolidated criteria for REporting Qualitative (COREQ) research principles were used in reporting study methods and findings. SETTING: Two Italian Bachelor of Nursing degree programmes located in Northern Italy. PARTICIPANTS: Students attending their nursing programmes who a) had successfully passed one or more theoretical examinations; b) had one or more clinical learning experiences in varied contexts (e.g. hospital, community); c) were attending the 1st, 2nd or 3rd year, and d) were willing to participate, were interviewed with an open-ended, face-to-face, audio-recorded interview. METHODS: A thematic analysis was performed. RESULTS: Participating students (n = 18) were between 20 and 25 years old and were attending the 1st to the 3rd (and final) academic year. Non-nursing tasks were experienced by them according to three main themes: a) "Being out of the scope of the learning experience," b) "Being forced by external and internal forces," and c) "Dealing with mixed outcomes by looking for a compromise." All students have reported learning to perform non-nursing tasks by shadowing clinical nurses and also practising these tasks by themselves. Internal and external forces prompted students to perform non-nursing tasks, which were recognised as having positive, negative, and neutral effects on themselves and on their learning outcomes. CONCLUSIONS: Non-nursing tasks are acquired since the beginning of the clinical experience, thus shaping the nursing students' professional identity. At the undergraduate nursing level, strategies should be implemented to prevent the phenomena that a) threaten the acquisition of more complex nursing competences expected by patients and society, and b) shape future generations to be flexible and to perform different tasks, included those below their role.

Genetic Testing and Clinical Management Practices for Variants in Non-BRCA1/2 Breast (and Breast/Ovarian) Cancer Susceptibility Genes: An International Survey by the Evidence-Based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) Clinical Working Group.

PURPOSE: To describe a snapshot of international genetic testing practices, specifically regarding the use of multigene panels, for hereditary breast/ovarian cancers. We conducted a survey through the Evidence-Based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) consortium, covering questions about 16 non-BRCA1/2 genes. METHODS: Data were collected via in-person and paper/electronic surveys. ENIGMA members from around the world were invited to participate. Additional information was collected via country networks in the United Kingdom and in Italy. RESULTS: Responses from 61 cancer genetics practices across 20 countries showed that 16 genes were tested by > 50% of the centers, but only six (PALB2, TP53, PTEN, CHEK2, ATM, and BRIP1) were tested regularly. US centers tested the genes most often, whereas United Kingdom and Italian centers with no direct ENIGMA affiliation at the time of the survey were the least likely to regularly test them. Most centers tested the 16 genes through multigene panels; some centers tested TP53, PTEN, and other cancer syndrome-associated genes individually. Most centers reported (likely) pathogenic variants to patients and would test family members for such variants. Gene-specific guidelines for breast and ovarian cancer risk management were limited and differed among countries, especially with regard to starting age and type of imaging and risk-reducing surgery recommendations. CONCLUSION: Currently, a small number of genes beyond BRCA1/2 are routinely analyzed worldwide, and management guidelines are limited and largely based on expert opinion. To attain clinical implementation of multigene panel testing through evidence-based management practices, it is paramount that clinicians (and patients) participate in international initiatives that share panel testing data, interpret sequence variants, and collect prospective data to underpin risk estimates and evaluate the outcome of risk intervention strategies.

Relationship Between Different Subpopulations of Circulating CD4+ T-lymphocytes and Microvascular Structural Alterations in Humans.

BACKGROUND: Different components of the immune system, including innate and adaptive immunity (T-effector lymphocytes and T-regulatory lymphocytes-TREGs) may be involved in the development of hypertension. In addition, it was demonstrated in animal models that TREGs may prevent angiotensin II-induced hypertension and vascular injury/inflammation. However, no data are presently available in humans about possible relationships between T-lymphocyte subtypes and microvascular structural alterations. METHODS: For this purpose, in the present study, we enrolled 24 normotensive subjects and 12 hypertensive patients undergoing an elective surgical intervention. No sign of local or systemic inflammation was present. All patients underwent a biopsy of subcutaneous fat during surgery. Subcutaneous small resistance arteries were dissected and mounted on a wire myograph and the media to lumen ratio (M/L) was calculated. In addition, retinal arteriolar structure was evaluated noninvasively by scanning laser Doppler flowmetry. Capillary density in the nailfold, dorsum of the finger, and forearm were evaluated by videomicroscopy. A peripheral blood sample was obtained before surgery for assessment of T-lymphocyte subpopulations by flow cytometry. RESULTS: Significant negative correlations were observed between indices of microvascular structure (M/L of subcutaneous small arteries and wall to lumen ratio of retinal arterioles) and circulating TREG lymphocytes. A direct correlation was observed between M/L of subcutaneous small arteries and circulating Th17 lymphocytes. In addition, total capillary density was correlated with a TREG effector memory subpopulation. CONCLUSION: Our data suggest that some lymphocyte subpopulations may be related to microvascular remodeling, confirming previous animal data, and opening therapeutic possibilities.

Identical TP53 mutations in pelvic carcinosarcomas and associated serous tubal intraepithelial carcinomas provide evidence of their clonal relationship.

Pelvic carcinosarcomas (PCSs) are rare aggressive biphasic tumors that localize in the ovary, fallopian tube, or peritoneum and present frequently as bilateral disease. We undertook a morphological, p53 immunohistochemical and TP53 gene mutational analysis study in a single institution cohort of 16 PCSs in order to investigate the nature of bilateral tumors and to shed light on their origin and pathogenesis. Of the 16 patients, 10 presented with bilateral disease, 6 with a carcinosarcoma in both adnexa, and the remaining cases with a carcinosarcoma in one adnexum and a carcinoma in the opposite. The carcinoma component showed high-grade serous features in 13/16 of cases (81 %). In 10 patients (63 %), a serous tubal intraepithelial carcinoma (STIC) was found, in one case bilateral, making a total of 11 STICs. STIC was found only in cases with a carcinoma component with high-grade serous features. All 10 bilateral tumors and all 11 PCS-associated STICs showed a similar p53 immunostaining pattern. At mutation analysis of the TP53 gene, all five bilateral PCS contained an identical mutation in both localizations. Furthermore, a TP53 mutation was found in 8 of 10 STICs, with an identical mutation in the associated PCS. The finding of similar p53 immunostaining in all bilateral cases and identical TP53 mutations in most PCS-associated STIC provides evidence for a clonal relation between these neoplastic lesions, supporting a metastatic nature of bilateral PCS and suggesting that they have an extraovarian origin in a STIC.

MAX mutations cause hereditary and sporadic pheochromocytoma and paraganglioma.

PURPOSE: Pheochromocytomas (PCC) and paragangliomas (PGL) are genetically heterogeneous neural crest-derived neoplasms. Recently we identified germline mutations in a new tumor suppressor susceptibility gene, MAX (MYC-associated factor X), which predisposes carriers to PCC. How MAX mutations contribute to PCC/PGL and associated phenotypes remain unclear. This study aimed to examine the prevalence and associated phenotypic features of germline and somatic MAX mutations in PCC/PGL. DESIGN: We sequenced MAX in 1,694 patients with PCC or PGL (without mutations in other major susceptibility genes) from 17 independent referral centers. We screened for large deletions/duplications in 1,535 patients using a multiplex PCR-based method. Somatic mutations were searched for in tumors from an additional 245 patients. The frequency and type of MAX mutation was assessed overall and by clinical characteristics. RESULTS: Sixteen MAX pathogenic mutations were identified in 23 index patients. All had adrenal tumors, including 13 bilateral or multiple PCCs within the same gland (P < 0.001), 15.8% developed additional tumors at thoracoabdominal sites, and 37% had familial antecedents. Age at diagnosis was lower (P = 0.001) in MAX mutation carriers compared with nonmutated cases. Two patients (10.5%) developed metastatic disease. A mutation affecting MAX was found in five tumors, four of them confirmed as somatic (1.65%). MAX tumors were characterized by substantial increases in normetanephrine, associated with normal or minor increases in metanephrine. CONCLUSIONS: Germline mutations in MAX are responsible for 1.12% of PCC/PGL in patients without evidence of other known mutations and should be considered in the genetic work-up of these patients.

Clinically guided genetic screening in a large cohort of italian patients with pheochromocytomas and/or functional or nonfunctional paragangliomas.

PURPOSE: The aim of the study was to define the frequency of hereditary forms and the genotype/phenotype correlations in a large cohort of Italian patients with pheochromocytomas and/or functional or nonfunctional paragangliomas. DESIGN: We examined 501 consecutive patients with pheochromocytomas and/or paragangliomas (secreting or nonsecreting). Complete medical and family histories, as well as the results of clinical, laboratory, and imaging studies, were recorded in a database. Patients were divided into different groups according to their family history, the presence of lesions outside adrenals/paraganglia considered syndromic for VHL disease, MEN2, and NF1, and the number and types of pheochromocytomas and/or paragangliomas. Germ-line mutations in known susceptibility genes were investigated by gene sequencing (VHL, RET, SDHB, SDHC, SDHD) or diagnosed according to phenotype (NF1). In 160 patients younger than 50 yr with a wild-type profile, multiplex ligation-dependent probe amplification assays were performed to detect genomic rearrangements. RESULTS: Germline mutations were detected in 32.1% of cases, but frequencies varied widely depending on the classification criteria and ranged from 100% in patients with associated syndromic lesions to 11.6% in patients with a single tumor and a negative family history. The types and number of pheochromocytomas/paragangliomas as well as age at presentation and malignancy suggest which gene should be screened first. Genomic rearrangements were found in two of 160 patients (1.2%). CONCLUSIONS: The frequency of the hereditary forms of pheochromocytoma/paraganglioma varies depending on the family history and the clinical presentation. A positive family history and an accurate clinical evaluation of patients are strong indicators of which genes should be screened first.

Combined decrease of defined B and T cell subsets in a group of common variable immunodeficiency patients.

Common variable immunodeficiency disease (CVID) is a primary immune disorder affecting B cells and characterized by hypogammaglobulinemia and recurrent infections. To elucidate the clinical and immunological heterogeneity of this condition, we have studied B and T cell subsets in 25 CVID patients. In eleven of them, we observed a remarkable relative expansion of a B cell subpopulation (CD19(hi)/CD21(lo) cells) characterized by the absence of CD23 and the reduced expression of the chemokine receptors CXCR5 and CCR7. Our analyses demonstrated in these patients that the expansion of CD19(hi)/CD21(lo) cells correlates with a selective decrease of circulating naïve and CD21(hi) memory B lymphocytes. The same group of patients displayed a simultaneous severe reduction of naïve CD4+ T cells associated with decreased levels of T cell receptor excision circles. These observations suggest that a combined defect in generation of B and T subpopulations may account for the abnormal immunophenotype characterizing this subgroup of CVID patients.

Reduced thymic output, increased spontaneous apoptosis and oligoclonal B cells in polyethylene glycol-adenosine deaminase-treated patients.

Impairment of purine metabolism due to adenosine deaminase (ADA) deficiency is associated with a severe combined immunodeficiency (SCID). Polyethylene glycol-modified ADA (PEG-ADA) has provided noncurative, life-saving treatment for these patients, but full immune recovery is not achieved with this therapy. Since ADA-SCID is perhaps the most difficult form of SCID to handle clinically, understanding the benefits and limitations of PEG-ADA therapy may be relevant for treatment selection. To this purpose, we analyzed the rate of thymic output, T and B cell repertoires, number of T cell divisions, IFN-gamma and IL-4 production, and the extent of cell death in five ADA-SCID patients following a prolonged period of treatment with PEG-ADA. We found that thymic output was low in these patients. However, their T cell repertoire was heterogeneous, and their T lymphocytes produced cytokines upon activation and responded to mitogen stimulation, although with different kinetics. Furthermore, a high number of peripheral T lymphocytes were committed to apoptosis. Anomalies were also observed in the B cell compartment, with oligoclonal expansions of B cell clonotypes in two patients. Our data indicate that decreased thymic function, B cell oligoclonality, and increased spontaneous apoptosis may be the mechanisms by which the immunodeficiency of ADA-SCID patients persists in spite of treatment with PEG-ADA.

Interleukin-7 receptor alpha (IL-7Ralpha) deficiency: cellular and molecular bases. Analysis of clinical, immunological, and molecular features in 16 novel patients.

Analysis of gene-targeted mice and patients with severe combined immunodeficiency due to mutations of the alpha chain of the interleukin-7 receptor (IL-7Ralpha) has shown important differences between mice and humans in the role played by IL-7 in lymphoid development. More recently, it has been shown that IL-7Ralpha is also shared by the receptor for another cytokine, thymic stromal lymphopoietin (TSLP). In this review, we discuss recent advances in IL-7- and TSLP-mediated signaling. We also report on the clinical and immunological features of 16 novel patients with IL-7Ralpha deficiency and discuss the results of hematopoietic stem cell transplantation.